QUANTITATIVE FATTY ACID SIGNATURE ANALYSIS: A NEW METHOD OF ESTIMATING PREDATOR DIETS

作者：Sara J. Iverson, Chris Field, William Don Bowen, Wade Blanchard · 发表于：Ecological Monographs · 年份：2004 · DOI：10.1890/02-4105 · 被引用次数：740 · 研究领域：Marine animal studies overview、Isotope Analysis in Ecology、Marine and fisheries research

Accurate estimates of the diets of predators are required in many areas of ecology, but for many species current methods are imprecise, limited to the last meal, and often biased. The diversity of fatty acids and their patterns in organisms, coupled with the narrow limitations on their biosynthesis, properties of digestion in monogastric animals, and the prevalence of large storage reservoirs of lipid in many predators, led us to propose the use of quantitative fatty acid signature analysis (QFASA) to study predator diets. We present a statistical model that provides quantitative estimates of the proportions of prey species in the diets of individual predators using fatty acid signatures. We conducted simulation studies using a database of 28 prey species (n= 954 individuals) from the Scotian Shelf off eastern Canada to investigate properties of the model and to evaluate the reliability with which prey could be distinguished in the model. We then conducted experiments on grey seals ( Halichoerus grypus ,n= 25) and harp seals ( Phoca groenlandica ,n= 5) to assess quantitative characteristics of fatty acid deposition and to develop calibration coefficients for individual fatty acids to account for predator lipid metabolism. We then tested the model and calibration coefficients by estimating the diets of experimentally fed captive grey seals (n= 6, switched from herring to a mackerel/capelin diet) and mink kits ( Mustela vison ,n= 46, switched from milk to one of three oil‐suppl...